“…For example, exogenous auxin or enhanced sensitivity to auxin inhibited nodule formation in Medicago truncatula (Breakspear et al, ; Hobecker et al, ; van Noorden, Ross, Reid, Barry, & Ulrike, ) and conversely resistance to auxin resulted in enhanced nodule development in this species (Kuppusamy et al, ). In soybean, enhanced sensitivity to auxin resulted in reduced nodule formation (Wang et al, ) and was associated with reduced sensitivity to CK (Turner et al, ). Exogenous CK restored nodule numbers in these roots, suggesting that the underlying reason for reduced nodulation in auxin hypersensitive roots is reduced CK activity (Nizampatnam, Schreier, Damodaran, Adhikari, & Subramanian, ).…”